<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>Title</title>
  <style>
    [v-cloak] {
      display: none;
    }
  </style>
</head>
<body>

<div id="app" v-cloak>
  <h2 v-if="score>=90">优秀</h2>
  <h2 v-else-if="score>=80">良好</h2>
  <h2 v-else-if="score>=60">及格</h2>
  <h2 v-else>不及格</h2>
</div>

<script src="../js/vue.js"></script>
<script>
  const app = new Vue({
    el: '#app',
    data: {
      score: 99
    }
  })
</script>

</body>
</html>